Haemolytic Anaemia Flashcards
What are some inherited causes of haemolytic anaemia? (5)
• Hereditary spherocytosis
• Hereditary elliptocytosis
• Thalassaemia
• Sickle cell anaemia
• G6PD deficiency
What are some acquired causes of haemolytic anaemia? (5)
• Autoimmune haemolytic anaemia
• Alloimmune haemolytic anaemia (e.g., transfusions reactions and haemolytic disease of newborn)
• Paroxysmal nocturnal haemoglobinuria
• Microangiopathic haemolytic anaemia
• Prosthetic valve-related haemolysis
What are the main features of haemolytic anaemia? (3)
• Anaemia
• Splenomegaly (the spleen becomes filled with destroyed red blood cells)
Jaundice (bilirubin is released during the destruction of red blood cells)
What is shown in haemolytic anaemia on an fbc?
Normocytic anaemia
What is shown on a blood film in haemolytic anaemia?
Schistocytes
Which anaemia is a direct Coombs test positive in?
Autoimmune haemolytic anaemia
Which ethnic group is hereditary spherocytosis most common in?
Northern Europeans
What type of genetic condition is hereditary spherocytosis? E.g. dominant
Autosomal dominant
What is hereditary spherocytosis?
fragile, sphere-shaped red blood cells that easily break down when passing through the spleen
What are the presenting features of hereditary spherocytosis? (4)
Anaemia
Jaundice
Gallstones
Splenomegaly
What is aplastic crisis in hereditary spherocytosis caused by?
Parovirus b19
What is found on fbc in hereditary spherocytosis?
Raised mean corpuscular haemoglobin concentration (MCHC)
What is seen on a blood film in hereditary spherocytosis? (2)
Increased reticulocyte count
Spherocytes
What is the management of hereditary spherocytosis? (4)
Folate supplements
Blood transfusion
Splenectomy
Cholecystectomy if gallstones become a problem
What is hereditary elliptocytosis?
Hereditary elliptocytosis is similar to hereditary spherocytosis except that the red blood cells are ellipse-shaped.
Cause of haemolytic anaemia
What type of genetic condition is hereditary elliptocytosis? E.g. dominant
Autosomal dominant
What is the function of glucose-6-phosphate dehydrogenase?
enzyme responsible for protecting the cells from oxidative damage.
What type of genetic condition is G6PD deficiency? E.g. dominant
X-linked recessive
Which ethnic groups is G6PD deficiency most common in? (3)
Mediterranean
Asian
African
Which gender is G6PD deficiency most common in?
Men
What are some triggers of acute episodes of haemolytic anaemia in G6PD deficiency? (3) (give examples of one of these categories)
Infections
Drugs e.g. ciprofloxacin, sulfonylureas (e.g., gliclazide) and sulfasalazine.
Fava beans
What are the presenting features of G6PD deficiency? (4)
Jaundice (often in neonatal period)
Gallstones
Anaemia
Splenomegaly
What is seen on a blood film in G6PD deficiency? (3)
Heinz bodies
Bite cells
Blister cells
What is used to diagnose G6PD deficiency?
G6PD enzyme assay
Which valves can cause haemolytic anaemia?
Both bioprostheitc and metallic valves
How do you manage haemolytic anaemia due to prosthetic valves? (4)
• Monitoring
• Oral iron and folic acid supplementation
• Blood transfusions if severe
• Revision surgery may be required in severe cases
What are the 2 types of autoimmune haemolytic anaemia?
Warm
Cold
What is autoimmune haemolytic anaemia?
when antibodies are created against the patient’s red blood cells. These antibodies lead to red blood cell destruction (haemolysis)
What is the most common type of autoimmune haemolytic anaemia?
Warm
What is the cause of warm autoimmune haemolytic anaemia?
Idiopathic
What is cold-reactive autoimmune haemolytic anaemia?
Aka cold agglutination disease
antibodies attach to the red blood cells and cause them to clump together, called agglutination. The immune system is activated, and the red blood cells are destroyed
What are the causes of cold-reactive autoimmune haemolytic anaemia? (4)
Lymphoma
Leukaemia
SLE
Infections (e.g., mycoplasma, EBV, CMV and HIV).
What is the management of autoimmune haemolytic anaemia? (4)
• Blood transfusions
• Prednisolone
• Rituximab (a monoclonal antibody against B cells)
• Splenectomy
What is alloimmune haemolytic anaemia?
occurs due to foreign red blood cells or foreign antibodies.
What are the 2 causes of alloimmune haemolytic anaemia?
Transfusion reactions
Haemolytic disease of the newborn (rhesus)
What is a haemolytic transfusion reaction?
occur when red blood cells are transfused into the patient. The immune system produces antibodies against antigens on the foreign red blood cells. An immune response leads to the destruction of those foreign red blood cells.
What is the rhesus status of mum and baby in haemolytic disease of the newborn?
Mum = rhesus negative
Baby = rhesus positive
What is haemolytic disease of the newborn?
when maternal antibodies cross the placenta from the mother to the fetus. These maternal antibodies target antigens on the red blood cells of the fetus. These maternal antibodies destroy the neonate’s red blood cells. It occurs when the fetus is rhesus D positive (with rhesus D antigens on their red blood cells), and the mother is rhesus D negative (with no rhesus D antigens on her red blood cells). During a sensitisation event (e.g., antepartum haemorrhage), the mother can get exposed to the fetal red blood cells and start producing anti-D antibodies against the rhesus D antigen. In future, these antibodies can cross to the baby and cause haemolysis
How is sensitisation prevented in rhesus negative women?
Anti D prophylaxis
What is paroxysmal nocturnal haemoglobinuria caused by?
specific genetic mutation in the haematopoietic stem cells in the bone marrow
It results in a loss of the proteins on the surface of red blood cells that inhibit the complement cascade, allowing activation of the complement cascade on red blood cells and their destruction.
What is paroxysmal nocturnal haemoglobinuria?
Compliment cascade is activated too much and RBCs are destroyed
Due to loss of proteins that usually inhibit complement cascade
What is the characteristic presenting symptom of paroxysmal haemoglobinuria?
Red urine in the morning
Contains haemoglobin and haemosiderin.
What are the presenting features of paroxysmal nocturnal haemoglobinuria? (4)
Red urine in the morning
Anaemia
Thrombosis (e.g. DVT and PE)
Smooth muscle dystopia (e.g. oesophageal spasm and erectile dysfunction)
What is the management of paroxysmal nocturnal haemoglobinuria? (2)
Eculizumab
Bone marrow transplant
What does eculizumab target and what is it used to treat?
Targets complement component 5 (C5)
Paroxysmal nocturnal haemoglobinuria
What is microangiopathic haemolytic anaemia?
involves the destruction of red blood cells as they travel through the circulation. This is most often caused by abnormal activation of the clotting system, with blood clots (thrombi) partially obstructing the small blood vessels, referred to as thrombotic microangiopathy. These obstructions churn the red blood cells, causing haemolysis (rupture). Picture a mesh inside the small blood vessels shredding the red blood cells.
What does microangiopathic haemolytic anaemia occur secondary from? (5)
• Haemolytic uraemic syndrome (HUS)
• Disseminated intravascular coagulation (DIC)
• Thrombotic thrombocytopenic purpura (TTP)
• Systemic lupus erythematosus (SLE)
• Cancer
What is found on a blood film in microangiopathic haemolytic anaemia?
Schistocytes
